hw/xen: pass PCI domain to xc_physdev_map_pirq_msi()

It's currently impossible for passthrough devices on segment different
than 0 to work correctly, as the PCI domain is not provided to
xc_physdev_map_pirq_msi(), and hence it's unconditionally assumed that
all devices are on segment 0.

Adjust the call to xc_physdev_map_pirq_msi() to pass the PCI domain in
the high 16bits of the bus parameter.  On versions of Xen where this
is not supported the passed segment will be ignored and assume to be 0,
no worse than the current state.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Frediano Ziglio <freddy77@gmail.com>
Reviewed-by: Anthony PERARD <anthony.perard@vates.tech>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
Message-ID: <20251017155136.16540-1-roger.pau@citrix.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>

hw/xen/xen_pt_msi.c

@@ -138,6 +138,7 @@ static int msi_msix_setup(XenPCIPassthroughState *s,
         rc = xc_physdev_map_pirq_msi(xen_xc, xen_domid, XEN_PT_AUTO_ASSIGN,
                                      ppirq, PCI_DEVFN(s->real_device.dev,
                                                       s->real_device.func),
+                                     ((uint32_t)s->real_device.domain << 16) |
                                      s->real_device.bus,
                                      msix_entry, table_base);
         if (rc) {